J/ApJ/856/142ivo://CDS.VizieR/J/ApJ/856/142doi:10.26093/cds/vizier.18560142CDSChiti A.Simon J.D.Frebel A.Thompson I.B.Shectman S.A.Mateo M.,Bailey J.I.Crane J.D.Walker M.2019-02-27T05:50:37Z2019-02-18T13:42:42ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frchemically-peculiar-starschemical-abundancesvisible-astronomyspectroscopyeffective-temperatureThe study of the chemical abundances of metal-poor stars in dwarf galaxies provides a venue to constrain paradigms of chemical enrichment and galaxy formation. Here we present metallicity and carbon abundance measurements of 100 stars in Sculptor from medium-resolution (R~2000) spectra taken with the Magellan/Michigan Fiber System mounted on the Magellan-Clay 6.5m telescope at Las Campanas Observatory. We identify 24 extremely metal-poor star candidates ([Fe/H]{<}-3.0) and 21 carbon-enhanced metal-poor (CEMP) star candidates. Eight carbon-enhanced stars are classified with at least 2{sigma} confidence, and five are confirmed as such with follow-up R~6000 observations using the Magellan Echellette Spectrograph on the Magellan-Baade 6.5m telescope. We measure a CEMP fraction of 36% for stars below [Fe/H]=-3.0, indicating that the prevalence of carbon-enhanced stars in Sculptor is similar to that of the halo (~43%) after excluding likely CEMP-s and CEMP-r/s stars from our sample. However, we do not detect that any CEMP stars are strongly enhanced in carbon ([C/Fe]>1.0). The existence of a large number of CEMP stars both in the halo and in Sculptor suggests that some halo CEMP stars may have originated from accreted early analogs of dwarf galaxies.2018ApJ...856..142Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/856/142CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/65 : Spectroscopically Selected Halo K Giants (Ratnatunga+ 1989)J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992)J/AJ/117/981 : Estimation of stellar metal abundance. II. (Beers+, 1999)J/AJ/130/1065 : Sculptor dwarf spheroidal galaxy members (Coleman+, 2005)J/AJ/130/2804 : Carbon abundances in metal-poor stars (Rossi+, 2005)J/ApJ/655/492 : Equivalent widths of 26 metal-poor stars (Aoki+, 2007)J/ApJ/682/1217 : Abundances in red giants in 7 GCs (Kirby+, 2008)J/ApJ/705/328 : Abundance measurements in Sculptor dSph (Kirby+, 2009)J/ApJS/182/80 : Rare earth abundances (Sneden+, 2009)J/AJ/137/3100 : Radial velocities of 4 dSph galaxies (Walker+, 2009)J/ApJ/724/341 : Nucleosynthesis of massive metal-free stars (Heger+, 2010)J/ApJS/191/352 : Abundances in stars of MW dwarf satellites (Kirby+, 2010)J/ApJ/711/350 : Metal-poor giant Boo-1137 abundances (Norris+, 2010)J/AJ/144/168 : Spectroscopy of Scl 1019417 and UMi 20103 (Kirby+, 2012)J/ApJ/779/102 : Metallicities of RGB stars in dwarf galaxies (Kirby+, 2013)J/ApJS/210/23 : Line intensities in CN transitions (Brooke+, 2014)J/A+A/571/A47 : Linelist of CH in stellar atmospheres (Masseron+, 2014)J/ApJ/797/21 : Carbon-enhanced metal-poor stars (Placco+, 2014)J/MNRAS/440/2665 : SDSS J021933.13+200830.2 spectroscopy (Roederer+, 2014)J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)J/ApJS/214/26 : Line lists for CN isotopes transitions (Sneden+, 2014)J/ApJ/807/171 : SkyMapper Survey metal-poor star spectro. (Jacobson+, 2015)J/ApJ/801/125 : Carbon in red giants in GCs and dSph galaxies (Kirby+, 2015)J/ApJ/802/93 : Abundance analysis of 5 stars in Sculptor (Simon+, 2015)J/A+A/580/A129 : Sulphur in the Sculptor dSph (Skuladottir+, 2015)J/A+A/574/A129 : First CEMP star in the Sculptor dSph (Skuladottir+, 2015)J/ApJ/817/53 : Fe-group abundance analysis in HD84937 (Sneden+, 2016)J/ApJ/833/20 : Carbon-enhanced metal-poor star abundances (Yoon+, 2016)J/A+A/606/A71 : dSph RGB abundance and velocities (Skuladottir+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/856/142https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/856/142http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/856/142https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/856/142https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/856/142http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/856/142GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/856/142/table5 (Stellar parameters and abundances from Magellan/MagE spectra)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/856/142/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/856/142/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/856/142/table5?GETtext/xml+votable180.050000true10.4159156-26.31512890.005555555555555556Cone search capability for table J/ApJ/856/142/table6 (Magellan-Clay/M2FS measurements)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/856/142/table6?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/856/142/table6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/856/142/table6?GETtext/xml+votable180.050000true14.6615417-33.58396670.0055555555555555566/16654 35549 35551 35720https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/856/142?format=asciiOpticaldefaultJ/ApJ/856/142/table5Stellar parameters and abundances from Magellan/MagE spectraIDSource namemeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintM2FSStar also observed with M2FS (link to table 6)meta.ref.urlintnullablef_ID[abd, ] Flag(s) on ID (1)meta.codecharSlit[0.7/1.0] Slit widtharcsecspect.line.widthfloatlog(g)[1/3.6] log surface gravitylog(cm.s**-2)phys.gravityfloatTeff[4513/5518] Effective temperatureKphys.temperature.effectiveintl_[Fe/H]KPLimit flag on [Fe/H]KPmeta.code.error;phys.abund.Fechar[Fe/H]KP[-4/-2.1]? log Fe/H number abundance from the KP indexlog(Sun)meta.idfloatnullablee_[Fe/H]KP[0.1/0.4]? Uncertainty in [Fe/H]KPlog(Sun)stat.error;phys.abund.Fefloatnullablel_A(C)Limit flag on A(C)meta.code.errorcharA(C)[4.8/8.3] Absolute carbon abundancelog(Sun)phys.abundfloate_A(C)[0.1/0.4]? Uncertainty in A(C)log(Sun)stat.errorfloatnullablel_[C/Fe]Limit flag on [C/Fe]meta.code.error;phys.abundchar[C/Fe][-0.6/2.6]? log C/Fe number abundancelog(Sun)meta.idfloatnullablee_[C/Fe][0.1/0.3]? Uncertainty in [C/Fe]log(Sun)stat.error;phys.abundfloatnullable[C/Fe]c[0/0.8]? log Fe/H number abundance correctionlog(Sun)phys.abundfloatnullablel_[C/Fe]cLimit flag on [C/Fe]corrmeta.code.error;phys.abundchar[C/Fe]f[-0.5/2.7]? Final log C/Fe number abundancelog(Sun)phys.abundfloatnullablee_[C/Fe]f[0.1/0.3]? Uncertainty in [C/Fe]finallog(Sun)stat.error;phys.abundfloatnullable[Ba/H][-0.7/0.8]? log Ba/H number abundancelog(Sun)phys.abundfloatnullableu_[Ba/H]Uncertainty flag on [Ba/H] (2)meta.code.error;phys.abundcharRAJ2000Right ascension (J2000) (3)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (3)degpos.eq.dec;meta.mainC05Display data from Coleman+, 2005, J/AJ/130/1065 if anymeta.ref.urlintnullableJ/ApJ/856/142/table6Magellan-Clay/M2FS measurementsl_[Fe/H]Limit flag on [Fe/H]meta.code.error;phys.abund.FecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTypeObject type (1)src.classcharMagEStar also observed with MagE (link to table 5)meta.ref.urlintnullableIDSource namemeta.id;meta.maincharprimaryf_ID[d] Flag on ID (2)meta.codecharRAJ2000[0/1] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[33] Degree of Declination (J2000)pos.eq.dec;meta.mainlog(g)[0.9/3.6] log surface gravitylog(cm.s**-2)phys.gravityfloatTeff[4451/5493] Effective temperatureKphys.temperature.effectiveint[Fe/H][-3.8/-0.6] log Fe/H number abundancelog(Sun)meta.idfloate_[Fe/H][0.1/0.9]? Uncertainty in [Fe/H]log(Sun)stat.error;phys.abund.Fefloatnullablel_[C/Fe]Limit flag on [C/Fe]meta.code.error;phys.abundchar[C/Fe][-1.4/0.9]? log C/Fe number abundancelog(Sun)meta.idfloatnullablee_[C/Fe][0.2/0.7]? Uncertainty in [C/Fe]log(Sun)stat.error;phys.abundfloatnullable[C/Fe]c[0/0.8]? log Fe/H number abundance correctionlog(Sun)phys.abundfloatnullablel_[C/Fe]fLimit flag on [C/Fe]finalmeta.code.error;phys.abundchar[C/Fe]f[-0.9/1.1]? Final log C/Fe number abundancelog(Sun)phys.abundfloatnullableC05Display data from Coleman+, 2005, J/AJ/130/1065 if anymeta.ref.urlintnullable